This thesis work proposes a design of a bioinspired robotic pectoral fin system based on the morphology and locomotion of a cownose ray (Rhinoptera bonasus) for the development of a bioinspired autonomous underwater robot. The cownose ray employs large paired pectoral fins for self-propulsion, whose locomotion is characterized by spanwise-flapping and chordwise harmonic traveling waves. The cownose ray swimming mode is largely investigated for the outstanding performances in terms of propulsion efficiency and maneuverability. The kinematics of cownose ray locomotion has been simulated thanks to a 3D bio-mechanical model, whose inputs are a meshed model of a pectoral fin and key kinematic parameters, such as flapping amplitude, flapping frequency and number of chordwise waves. The model output is the instantaneous space position of each point of the modeled pectoral fin. Thrust, power and efficiency of propulsion are estimated thanks to the integration of the bio-mechanical model and a 1D reactive model based on Lighthill theory. The results of the kinematic simulation are taken as input for an optimal bio-mimetic design of the pectoral fin system, which is powered by three 1-DOF multi-joint mechanisms driven by three respective independent servo-motors.
L'obiettivo di questa tesi consiste nella progettazione di un sistema bio-ispirato di pinna pettorale robotico basato sulla morfologia e sulla locomozione di una cownose ray (Rhinoptera bonasus) finalizzato allo sviluppo di un robot subacqueo autonomo bio-ispirato. La cownose ray nuota grazie all’utilizzato di pinne pettorali, la cui locomozione è caratterizzata dal movimento di trasversale di flappeggio e da onde armoniche longitudinali. Il modo di nuotare della cownose ray è noto per le eccezionali prestazioni in termini di efficienza di propulsione e manovrabilità. La locomozione della cownose ray è simulata cinematicamente grazie ad un modello 3D biomeccanico, che prende in input una mesh geometrica della pinna e parametri cinematici chiave, quali ampiezza, frequenza del flappeggio e numero di onde longitudinali. Il modello consente il calcolo della posizione istantanea di ciascun punto della pinna pettorale. La spinta, la potenza e l’efficienza della propulsione sono stimate grazie all’integrazione del modello 3D biomeccanico e di un modello reattivo 1D basato sulla teoria di Lighthill. I risultati della simulazione cinematica sono stati utilizzati come input per la progettazione ottima del sistema di pinna pettorale, composto da tre meccanismi multi-giunto 1 GDL alimentati da tre rispettivi servomotori indipendenti.
Underwater robot : design of a bioinspired pectoral fin system based on cownose ray locomotion
BONFATTI, FILIPPO
2018/2019
Abstract
This thesis work proposes a design of a bioinspired robotic pectoral fin system based on the morphology and locomotion of a cownose ray (Rhinoptera bonasus) for the development of a bioinspired autonomous underwater robot. The cownose ray employs large paired pectoral fins for self-propulsion, whose locomotion is characterized by spanwise-flapping and chordwise harmonic traveling waves. The cownose ray swimming mode is largely investigated for the outstanding performances in terms of propulsion efficiency and maneuverability. The kinematics of cownose ray locomotion has been simulated thanks to a 3D bio-mechanical model, whose inputs are a meshed model of a pectoral fin and key kinematic parameters, such as flapping amplitude, flapping frequency and number of chordwise waves. The model output is the instantaneous space position of each point of the modeled pectoral fin. Thrust, power and efficiency of propulsion are estimated thanks to the integration of the bio-mechanical model and a 1D reactive model based on Lighthill theory. The results of the kinematic simulation are taken as input for an optimal bio-mimetic design of the pectoral fin system, which is powered by three 1-DOF multi-joint mechanisms driven by three respective independent servo-motors.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/151542